US2986006A - Hydraulic directional control - Google Patents

Description

y 1961 w. T.- cox 2,986,006

HYDRAULIC DIRECTIONAL CONTROL Filed March 3, 1959 2 Sheets-Sheet l INVENTOR. M44 A9]! [0 May 30, 1961 w. T. cox

HYDRAULIC DIRECTIONAL CONTROL 2 Sheets-Sheet 2 Filed March 3, 1959 7'0 RESEQVO/R INVENTOR. Ma 6' 1: fax

United States Patent HYDRAULIC DIRECTIONAL CONTROL Willis T. Cox, 1021 Fruit St., Santa Ana, Calif.

Filed Mar. 3, 1959, Ser. No. 796,877

2 Claims. (Cl. 60-52) This invention relates to hydraulic apparatus for controlling the movement of an element having capability of Universal movement, or movement in all planes. The invention has been developed in connection with spraybooms carried by tank-cars on railroads, for the purpose of spraying the railroad right-of-way with herbicides. Such booms often are required to surmount obstacles or to change the direction of spraying. It will be obvious that the invention may be applied to many other elements handled in the same manner, and it is therefore not to be limited to railroad spray-booms, the term boom being used herein to denote any pole, beam, rod, nozzle or like implement.

In carrying out my invention, I use a lever mounted in a universal bearing and connected to two valve systems which may thereby be operated individually or in unison. The valve systems are each connected to a reservoir and to a pump, also connected to the reservoir, to assure a constant supply of fluid. A spray-boom is mounted to swing in vertical planes on a horizontal axis which in turn is mounted to swing in horizontal planes on a vertical axis. The pistons of hydraulic cylinders are connected to cranks by which each of the swinging movements are controlled. The cylinders are connected by two lines each, one line to each side of a piston-head, to respective ones of the foregoing valve systems. Movement of the lever causes the two valve systems to operate to cause liquid to flow reversibly in the respective two lines, and thus the pistons are moved to swing the spray-boom in any desired direction.

It is an object of my invention to provide means for controllingfrom a distance the direction in which an element such as a spray-boom points. Another object of my invention is to provide means, operable from a distance, for immediately retracting a spray-boom to a safe position, either pointing it upward or pointing it horizontally parallel to the car or other vehicle on which it is carried, when an object such as a signal tower or a train on a parallel track is encountered.

A further object of my invention is to provide a control system having only a single lever to be manipulated, so that the operator is able instantly to control the direc-. tional apparatus with only one hand.

Another object of my invention is to provide apparatus which will act automatically to retract a boom in the event an operator is not alert to the presence of an obstacle.

A more general object of my invention is to provide a hydraulic directional control which is simple to operate, economical to manufacture, and sturdy in construction so that it can withstand the rough usage and vibration incidental to railroad usage.

In the accompanying drawings, illustrative of a presently preferred embodiment of my invention but not intended to be limiting thereof, Fig. l is a perspective view showing my hydraulic directional control disposed upon a railroad car and controlling the position of a sprayboom;

Fig. 2 is a schematic diagram of the directional control apparatus;

Fig. 3 is a horizontal sectional view on the line 3-3 of Fig. 2 and on an enlarged scale;

Fig. 4 is a vertical sectional view on the line 44 of Fig. 3; and i Fig. 5 is a perspective view of the control lever and its mounting.

Having reference now to the details of the drawing, I have shown in Fig. 1 a railroad car 7 upon which are mounted one fixed end boom 8 for spraying between the rails 9, and two'laterally extending booms 10 for spraying at the sides of the right-of-way. The booms 10 are operated by the mechanism shown in greater detail in Figs. 2, 3, 4, and 5, and'are controlled from within the car 7 by a lever 11, to be seen shown in dotted line through the cars window. All of the booms are pro vided with spray nozzles 12 and are connected by hoses 13 to a tank (not shown) for spraying fluid within the car 7.

The lateral spray booms 10 are mounted on vertical shafts 15 which are secured rotatably to the car 7 by brackets 16. As the booms 10 are alike in mounting, operation, and control, a description of only one of them and its connected apparatus, as shown schematically in Fig. 2, will be sufiicient. A lever 17 is secured to the shaft 15 and its free end 18 is in turn secured pivotally to a piston rod 19 operating in a cylinder 20. The cylinder 20 has ears 21 at its'far end, pivoting on a pin 22 secured to the car 7 and permitting the necessary arcuate movement of the cylinder 20 when the lever 17 swings. The connection of the spray boom 10 to the shaft 15 is accom: plished by means of a bell-crank lever 23, the fulcrum of which is secured by a pivot pin 24 to the lower end of the shaft 15. The spray boom 10 is secured, as by welding, to one arm of the bell crank lever 23, and the other arm of the bell crank lever -23 is connected by a pivot pin 25 to a piston rod 26 operating in a cylinder 27. As in the case of the cylinder 20, the cylinder 27 has ears 2S pivoting on a pin 29 secured'to the car 7, to permit arcuate movement of the cylinder '27 when the lever 23 swings.

The piston rods 19 and 26 have, respectively piston heads 30 and 31 within the cylinders 20 and 27. The cylinder 20 is provided with two ports 32 and 33, one on each side of the piston head 30, and the cylinder 27 is likewise provided with two ports, 34 and 35, one on each side of the piston head 31. As will be seen hereinafter, all of the ports 32, 33, 34, an 35 function as both inlet and outlet ports; by the admission of fluid through port 32 into cylinder 20, and by the simultaneous release or" fluid from port 33, for examplathe piston rod 19 can be extended from the cylinder 20 and the shaft 15 so moved as to swing the boom 10 to an outwardly extended position relatively to the car 7. Conversely, when fluid is admitted through the port 33 and released through the port 32, the boom 10 will be moved to a retracted position alongside the car 7. Similarly the ports 34 and 35 admit or release fluid to cause the piston 26 to move the bellcrank lever 23 toswing the boom 10 downward, or upward to a vertical position parallel to the side of the car 7.

Fluid is supplied to the cylinders 20 and 27 by valves 40 and 41 illustrated in Fig. 2 and shown in greater detail for one valve in Fig. 3; Both valve 40 and valve 41 are connected to a reservoir (not shown) and to a pump (not shown). As the valves are alike in structure, only valve 40' is illustrated in detail. Valve 40 has an inlet conduit 42 from the pump which admits pressure fluid to the center portion of a cylindrical valve chamber 43. Opposite the inlet conduit 42 there is an outlet conduit 44, leading to the reservoir. Entrance of fluid to the outlet conduit 44 is controlled by a ball-check V Patented May 30, 1961 valve 45 and spring 46, which also prevents return flow through the conduit 44 to the central portion 43 of the valve 40. A valve stem 47 carries two valve heads 48 and 49 which slide within the chamber 43. Spaced from the ends of the chamber 43 so that both may be covered at the same time by the valve heads 48 and 49, and so that either may selectively be in communication with the inlet conduit 42, are exit ports 50 and 51. The ports 50 and 51 are, respectively, connected to the ports 32 and 33 of the cylinder 20 by conduits 52 and 53, which, as shown in Fig. 1, are of the flexible type, preferably of oil-resistant artificial rubber. The elastic structure of conduits 52 and 53 permits them to expand resiliently to accommodate any momentary excess of fluid displaced by movement of the piston rods 19 and 26 as the rods enter and leave the cylinders 20 and 27.

The valve 41 is the same in internal structure as the valve 40, and has inlet 54 and outlet 55 connecting it respectively to the hereinbefore mentioned pump and reservoir. Dual exit ports 56 and 57, arranged to be closed simultaneously or opened selectively by movement of the valve stem 58, are connected by conduits 59 and 60, similar to conduits 52 and 53, to the ports 34 and 35, respectively, of the cylinder 27.

Movement of the valve stems 47 and 58 is effected by the control lever 11. The lever 11 has a ball foot 62 mounted to pivot on a pin 63. The pin 63 is carried by a gimbal ring 64 which in turn pivots on pins 65, 66 mounted in bearings 67 secured to the floor or other convenient part of the car 7. The lever 11 thus may be moved in any vertical plane intersecting the center of the gimbal ring 64. Below the ball foot 62, which serves as fulcrum, the lever 11 has an end 68, rectangular in shape and fitting into a rectangular hole 69 in a wobble plate 70. The valve stems 47 and 58 are pivotally connected by pins 71 to links 72 and 73, respectively, and the links 72 and 73 are likewise pivotally connected by pins 74 to the wobble plate 70.

Thus by movement of the wobble plate 70, in response to movement of the lever 11, the valve ports 50, 51, 56 and 57 may all be closed; any one of these ports may be selectively opened to inlet flow while the other three remain closed; or one port of each pair of ports may be opened while the other two ports (one on each valve) remain closed. By the consequent supply of fluid to one end or the other of the cylinders 20 and/ or 27, the boom 10 may be swung up or down or out or in, or in any noncontradictory combination of such movements. When the operator deems the movement in any direction to be suiiicient, he returns the lever to the neutral position in which the valve ports governing movement in that direction are closed. Fluid entering that particular valve from the pump then returns to the reservoir through the spring-controlled ball-check valve of the reservoir outlet 44 or 55. Such return circulation of the fluid is the normal condition of the system when the boom is not being swung and the outlet ports of a valve are both closed; it is also the condition when the boom meets an obstacle while moving, which might be a stop at the end of the booms traverse.

As it may sometimes happen that the operator might not be alert to an impending obstacle, I have provided automatic release mechanism which permits the boom 10 to swing upward or backward. A one-way pressure-responsive valve 75, which may be any standard valve of the type specified, is connected between the extension conduit 52 and the retraction conduit 53 with flow permitted only toward the retraction conduit. Let it be assumed that an obstacle is encountered while the lever 11 is in neutral position, with the outlet ports 50 and 51 of the valve 40 both closed, and consequently with the fluid in the lines 52 and 53 and in the cylinder 20 at a standstill. As the boom 10 tries to swing back, the piston head 30 will press toward the closed end of the cylinder; the fluid, not being permitted to re-enter the valve 40,

will flow around through the valve 75 to the other side of the piston head 30, and the effect will be the same as if fluid came through the conduit 53 from the valve 40. Likewise a similar one-way pressure responsive valve 76 is placed between the conduits 59 and 60, with flow permitted in the direction of conduit 60. The valve 76 permits the fluid in the lower end of the cylinder 27 to escape to the upper end of the cylinder when under strong pressure and unable to return to the valve 41.

The disclosed embodiment is not to be construed as a limitation upon my invention, the scope of which is deemed to include any desirable constructive modification within the spirit and breadth of the appended claims.

I claim:

1. Apparatus for hydraulically controlling the direction of a boom or similar element comprising: an arm, mounted to swing about its own axis; a lever connected to said arm for so swinging said arm; a pivot for said element at one end of said arm, about which said element may swing in planes containing said arm axis; a second lever connected to said element, for so swinging said element; a cylinder and a piston therein, respective to each of said levers, said pistons being operatively connected to the respective levers; said cylinders each having a pair of conduits for fluids opening into said cylinders on opposite sides of the heads of said pistons, whereby to reciprocate said pistons; a by-pass connecting the conduits respective to each cylinder and a check valve in each by-pass, for by-passing fluid pressure in the event said element encounters an obstacle; a four-way valve respective to each of said cylinders, each of said four-way valves controlling outlets to both of said conduits leading to the respective cylinder, an inlet and a third outlet; a reservoir for fluid having connections to both of said third outlets; springcontrolled check valves between each of said third outlets and said reservoir, permitting flow from said third outlets to said reservoir in the event neither of the other outlets is open; a pump having connections to said reservoir and to said inlets; a control lever pivotally mounted for universal angular movement; a wobble plate into which an end of said lever extends; and linkages operatively connecting each of said four-way valves to said wobble plate at angles to each other whereby lever-actuated movement of said wobble-plate efiects selective opening and closure of said four-way valves.

2. Apparatus for hydraulically controlling the direction of a spray boom on a vehicle comprising: a cylinder; a piston having a piston head reciprocable within said cylinder; said cylinder having fluid connections for hydraulic operation of said piston, on both sides of said piston head; means connecting said piston to said boom whereby reciprocating movement of said piston and swinging movement of said boom occur mutually; said fluid connections being flexible and having elasticity sufficient to permit expansion to receive fluid displaced into said connections by said piston; a single by-pass conduit connecting said fluid connections; and a spring-biased check-valve in said conduit yielding to permit fluid to pass from one side of said piston head to the other side of said piston head in response to pressure on said boom suflicient to overcome the bias of said check-valve, said check valve preventing flow between said fluid connections in the opposite direction, whereby after flow has occurred through said conduit said boom can be returned to its former position only in response to flow through said fluid connections.

References Cited in the file of this patent UNITED STATES PATENTS 2,330,567 Ehrenberg Sept. 28, 1943 2,424,288 Severy July 22, 1947 2,643,515 Harsch June 30, 1953 2,877,660 Rush Mar. 17, 1959

Images